Instructions

Air Brakes

This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a written test. The test consists of 25 multiple choice.. Read More

This endorsement is required for driving a vehicle with air brakes. To receive this endorsement, applicants must pass a written test. The test consists of 25 multiple choice questions. Each question has two, three or four answer choices. To pass, the applicant must answer at least 20 questions correctly. Test questions come from the Utah Commercial Driver License Handbook. Questions come from the chapter covering: Air Brakes. The Air Brakes endorsement may be used with the Class A, B or C CDL.

Number of Question 25

Passing Score 20

1. Emergency brakes are:

Not required on trucks.

Only required on trailers.

Required on tractors.

Only required when transporting hazardous materials.

All trucks, truck tractors, and buses must be equipped with emergency brakes and parking brakes.

2. When starting a vehicle with dual air brakes, pressure of ____ should be built up in the system before it is driven.

10 psi

25 psi

100 psi

200 psi

Before driving a vehicle with a dual air brake system, allow time for the air compressor to build up pressure of at least 100 psi in both the primary and secondary systems.

3. If braking at a speed of 55 mph while driving on dry pavement, the brake lag can add ____ to your vehicle's total stopping distance.

32 feet

15 feet

50 feet

10 feet

The total stopping distance for vehicles equipped with air brakes is made up of four factors: perception distance, reaction distance, brake lag distance, and braking distance. When braking at a speed of 55 mph while driving on dry pavement, the brake lag can add around 32 feet to a vehicle's total stopping distance.

4. Air tank drains should:

Not be used by the driver.

Only be used when it is wet outside.

Be used to drain the tanks completely.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Manually operated air tank drains must be opened daily to remove this build-up.

5. What should happen if the air pressure in the air brake system tanks falls below 60 psi?

A warning light should come on.

Lights should flash on the outside of the vehicle.

A message should appear on the control panel.

The vehicle should stop.

On vehicles with air brakes, a low air pressure warning signal will come on if the pressure in the air tanks falls below 60 psi. On large buses, the signal may activate at 80 to 85 psi.

6. Truck tractors with air brakes built on or after March 1, 1997 must have:

An Anti-Lock Braking System (ABS).

Bluetooth.

A GPS.

Truck tractors with air brakes built on or after March 1, 1997, and other vehicles with air brakes built on or after March 1, 1998, must be equipped with anti-lock brakes.

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